Many of our customers run Plumtree on Oracle, for better or worse.
Despite it's complexities and eccentricities, it's been a good platform albeit not without it's driver issues, configuration issues and other weirdnesses.
While doing some research on running Oracle over TCPS (TCP + SSL), I discovered two excellent Oracle resources in the blogosphere:
1. http://vanbortel.blogspot.com
2. http://tkyte.blogspot.com
Enjoy!